Mentions:
To assess the stability of the results of this meta-analysis, sensitivity analysis was performed by sequentially excluding each study. As shown in Figure 3, sensitivity analyses indicated that the three independent studies by Shin et al. [18], Shaker et al. [39] and Trajkov et al. [29] were the main origin of the heterogeneity in the overall comparisons. The heterogeneity was obviously decreased after exclusion of these three studies (G vs. A: OR = 0.69, 95%CI = 0.61–0.78, P<0.00001, I2 = 35%; GA+AA vs. GG: OR = 1.51, 95%CI = 1.31–1.73, P<0.00001, I2 = 37%). Meanwhile, similar result was obtained when any single study was omitted (Figure 3). Furthermore, the pooled ORs were not significantly altered after omitting the studies which the sample size was less than 50 cases in each group (OR = 1.38, 95%CI = 1.13–1.67, P<0.001), indicating that the results of this meta-analysis were relatively stable. The shape of the funnel plot seemed symmetrical (Figure 4), and neither Egger’s test nor Begg’s test indicated any significant publication bias (P = 0.191 and 0.286, respectively).

Mentions:
To assess the stability of the results of this meta-analysis, sensitivity analysis was performed by sequentially excluding each study. As shown in Figure 3, sensitivity analyses indicated that the three independent studies by Shin et al. [18], Shaker et al. [39] and Trajkov et al. [29] were the main origin of the heterogeneity in the overall comparisons. The heterogeneity was obviously decreased after exclusion of these three studies (G vs. A: OR = 0.69, 95%CI = 0.61–0.78, P<0.00001, I2 = 35%; GA+AA vs. GG: OR = 1.51, 95%CI = 1.31–1.73, P<0.00001, I2 = 37%). Meanwhile, similar result was obtained when any single study was omitted (Figure 3). Furthermore, the pooled ORs were not significantly altered after omitting the studies which the sample size was less than 50 cases in each group (OR = 1.38, 95%CI = 1.13–1.67, P<0.001), indicating that the results of this meta-analysis were relatively stable. The shape of the funnel plot seemed symmetrical (Figure 4), and neither Egger’s test nor Begg’s test indicated any significant publication bias (P = 0.191 and 0.286, respectively).